New spectacles and complaints
Transcription
New spectacles and complaints
New spectacles and complaints Viviane De Vries Non-adaptation complaints Asthenopia Blurred vision Distortion Deformation Tunnel vision ... Non-adaptation complaints Key factors for success in fitting Prescribing Advising Delivery Troubleshooting Prescribing: Refraction Refraction procedure (phoropter / trial frame) Accommodation (amplitude) Convergence (insufficiency and excess) Phorias Astigmatism (cyl -0.25D yes or no) Binocular balance Prescribing: Refraction (personal data) Prismatic correction Measured working distance Addition measurement in trial frame (several positions / methods) Advising: History (Unifocal) Previous correction Previous centration Design (spherical / aspherical) Material / refractive index / Abbe number History: Previous centration Optical Centre – Center Distance outwards & minus lenses Unnecessary divergence PD = 30mm CD = 33mm Prism base nasal (in) PD = 30mm CD = 33mm Compensation: the eye needs to converge Pupil Distance and center distance are not “in balance” Interaction distance – near: distortion History: Previous centration Complaints Centre Distance inwards & minus lenses Unnecessary convergence PD = 33mm CD = 30mm Prism base temporal (out) PD = 33mm CD = 30mm Compensation: the eye needs to diverge Pupil Distance and center distance are not “in balance” Interaction distance – near: distortion History: Previous centration Complaints Centre Distance outwards & plus lenses Unnecessary convergence PD = 30mm CD = 32mm Prism base temporal (out) PD = 30mm CD = 32mm Compensation: the eye needs to diverge Pupil Distance and center distance are not “in balance” Interaction distance – near: distortion History: Previous centration Complaints Centre Distance inwards & plus lenses Unnecessary divergence PD = 32mm CD = 30mm Prism base nasal (in) PD = 32mm CD = 30mm Compensation: the eye needs to converge Pupil Distance and center distance are not “in balance” Interaction distance – near: distortion History: Material / refractive index Abbe number Abbe 58 (n=1.5) Abbe 41 (n=1.6) Abbe 31 (n=1.67) Advising: History (Progressive) Generation I (Varilux I) Generation II (Varilux II) Generation III (Horizontal symmetry) Generation IV (Variable inset) Generation V (Individualisation) Advising: History (Progressive) Previous correction Previous centration Design (spherical / aspherical) Design (hard / soft) Design (front / back / integrated dubble) Material / refractive index / Abbe number History: Previous correction Spherical correction Cylindre Axis Addition level Reduction prism Prismatic correction Centration of progressives Indication for far on the stamp in the center of the pupil Depending on the advice of the manufacturer Indication for far on the stamp, 1 to 2 mm below the center of the pupil Centration based on near vision using the mirror test Always consider the basic rules for grinding! History: Previous centration Monocular Pupil Distance Fitting procedure 8-10mm Center Pupil Half B-size B-size “functional space” Check fitting height center of Pupil in “zero” direction Measure monocular PD Check monocular PD right Check monocular PD left History: “Hard” or “Soft” design Hyperopic presbyopes require long corridor length and “Soft design” Myopic presbyopes require short corridor length and “Hard design” Hyperopia Myopia Virtual Image to the prism top Virtual Image to the prism top long corridor length short corridor length Figure stamp /engravings Yellow figure stamp Blue figure stamp Template for centration “Hard” progressive Myopia Head movers Small frames Young presbyopes Low additions History “Soft” progressive Hyperopia Eye movers Large frames Experienced presbyopes High additions History Classification by design Classic designs Advanced designs “Basic designs ” for the “price sensitive” users “Quality designs ” for those who are willing to pay for quality and functionality “High quality designs ” for presbyopes who want more than a progressive lens “Advanced designs” for those modern presbyopes who like to experience “top of the top” FreeForm Technology The advanced designs FreeForm optical surfaces high speed cutting for Freely Definable Mathematical Parameters Eyeball rotation based calculation Balanced View Control (distorsion control) Listing’s Law History: Front or back design “Front” or “Back”? “Front": eye ball rotation easier to read part “Front”: less wide intermediate zone and reading part (more vertex distance) “Front” or “Back”? “Back": eye ball rotation is larger “Back”: wider intermediate zone and reading part (vertex distance = smaller) Twin design “front” and “back” The main characteristic is that both the benefits and advantages of the front and the back are placed on the right place. Classification by design Front Surface Design Back Surface Design Hoyalux GP/ Wide Rodenstock Impression Rodenstock Multigressiv Rodenstock Freesign Seiko P-1 Tokai BS Nikon Presio Essilor Ipseo Hoyalux Summit Pro/ Summit CD Zeiss Gradal HS Zeiss Individual Essilor Physio Anateo Hoyalux iD Integrated Double surface design Hoyalux iD LifeStyle Advanced Back Surface controlled design Advising: Personal data Centration (height) Pupildistance Monocular PD Variable Inset Inset of choice Reduction prism Vertex distance Pantoscopic angle Frame face form angle Head movement Eye movement Fitting procedure Zone length & minimum space Eye Point – top rim 10mm at least Eye point – bottom rim 14mm zone length 11mm zone length at least 18mm at least 14mm tolerance 2mm tolerance 1mm tolerance 1mm Fitting procedure Angle of inclination recommended angle = 8 -12 degrees Vertex Distance recommended vertex distance = 12.5mm Variable inset Inset is determined by the manufacturer Average 2.5 mm nasally compared to distant part Variable: depending on the distance correction Variable inset The more hyperopic, the greater the inset because the stronger the convergence The more myopic, the smaller the inset because the weaker convergence Fitting procedure: Variable Inset Fixation point Fixation point C Less inset for (-)power Divergence More inset for (+)power Convergence Inset of choice From 0 to 6 mm Convergence (insufficiency / excess) Amblyopia Anisometropia Small pupildistance Large pupildistance High hyperopia Reduction prism Value: Prism = O.67 X addition Influence Tradition Sheedy en Parsons Vertical prism < 2 prismatic dioptries Vertical prism > 4 prismatic dioptries Advising: Life style Troubleshooting Refraction Design History Centration Thank you !